Conventionally, a two-liquid mixing type method of mixing a first raw material and a second raw material to form a sealant or an adhesive is known. This two-liquid mixing type of sealant or adhesive is used as sealing or bonding means for filling gaps of connecting parts or joints of various structures such as an aircraft. In this two-liquid mixing type of sealant, a first raw material and a second raw material individually have liquidity at room temperature. However, when two raw materials are mixed once, a curing reaction is started and the mixture is cured after a predetermined time. However, the mixing of the first raw material and the second raw material for every work operation using the two-liquid mixing type of sealant or the like lowers work efficiency. Accordingly, the first raw material and the second raw material are mixed in advance in low-temperature circumstances to form a two-liquid mixing type of sealant, containers are rapidly filled with the two-liquid mixing type of sealant, and the containers are quickly frozen and are then stored in a freezer. At the time of use, the two-liquid mixing type of sealant is used by taking out the containers from the freezer and defrosting them.
A sealant-filling apparatus for filling a container with a two-liquid mixing type of sealant is known which includes a first feed unit that feeds a first raw material through a first flow channel and a second feed unit that feeds a second raw material through a second flow channel (for example, see PTL 1). The sealant-filling apparatus includes a third flow channel into which the first flow channel and the second flow channel are merged and through which the first raw material and the second raw material pass. The sealant-filling apparatus mixes at least two kinds of raw materials. A mixer for mixing the first raw material and the second raw material is disposed in the third flow channel, and the mixed material obtained from the mixer is discharged through a fourth flow channel. The sealant-filling apparatus includes a system pressure reducer that causes at least the mixer to be a pressure-reduced atmosphere before mixing the first raw material and the second raw material.
The sealant-filling apparatus respectively agitates the first raw material and the second raw material under reduced pressure before mixing the first raw material and the second raw material. Then, by mixing the first raw material and the second raw material after causing the mixer to enter the pressure-reduced atmosphere, the mixing of air in the course of mixing is reduced and no burst occurs when the resultant sealant is ejected from a cartridge.